During the process of preparing ethanol from starches, such as those found in corn grain, the carbohydrates comprising the starches must undergo a number of process stages so as to prepare a saccharide, such as glucose, for final fermentation. These stages include “extraction,” “cooking,” “conversion,” and “sterilization,” followed by cooling and fermentation. The extraction, cooking, conversion, and sterilization stages can be efficiently accomplished on a continuous basis using a steam injection device known as a “jet cooker” for the “cooking” stage. The “jet cooker” was adopted from the paper pulp processing industry.
Approximately 150 psi of steam is necessary for starch cooking. Steam boilers capable of producing the 150 psi of steam are expensive, heavy, and dangerous. Proper operation of these steam boilers often requires advanced knowledge or certification of proper construction, operation, and installation procedures. Further, given the high amount of pressure necessary for cooking, including for jet cooking, the technique of continuous jet cooking for small or portable fermentation process installations has been unavailable. Accordingly, the benefits of continuous direct stream injection cookers has been solely the privilege of large processing plants where the cookers have capacities characterized by pipe diameters of larger than two-and-one-half inches. There is a need for a jet cooker apparatus that is available for small or portable fermentation process installations, and, particularly, to have a jet cooker apparatus available for smaller, remote processors working in a scale as small as one-and-one-fourth inch pipe diameters.
Further, prior art steam heaters for transporting and converting vegetable starch do not teach an integrated system containing the three necessary components for jet cooking, i.e., an injector, a reactor, and a boiler. Rather, the prior art apparatuses use a non-integrated boiler to generate the steam to be injected into a process tube, that acts as a reactor in which the process fluid cooks. There is a need for a heater that is an integrated system of the three necessary components so as to accommodate small-scale processes.